#include <iostream>
using namespace std;

class Operation{
protected:
	double numA;
	double numB;
public:
	void setNumA(double numA) { this->numA = numA; }
	void setNumB(double numB) { this->numB = numB; }
	virtual double getResult() const  = 0;
};

class Add : public Operation{
public:
	double getResult() const { return numA + numB; }
};

class Mul : public Operation{
public:
	double getResult() const { return numA * numB; }
};
